the locking up is just simple lack of mem. resoruces. bit rot. or bad program.

it might be something else i see you have the ie5.5sp2 update. might as update to the ie6 it has more safty features in and more bug fixe's then the what you have.

and it never hurts to get a local program of the antivirus ones on your computer as well a firewall.

and never open any exe from some one you don't know or from some one you do know reason being they might have a virus that sent it out without their know about it.

best to save it in the email then ask them before you open it. if they sent it and know about it, then it might be alright.

but scan it anyway. :) never can tell it might have picked up a cold on the way to ya? :D

stay safe.